[libvirt] [PATCH v2 5/7] conf: Introduce new <hostdev> attribute 'display'

[Erik Skultety]

On Tue, Jul 10, 2018 at 01:39:03PM +0200, Michal Privoznik wrote:
> On 07/09/2018 06:24 PM, Erik Skultety wrote:
> > QEMU 2.12 introduced a new type of display for mediated devices using
> > vfio-pci backend which allows a mediated device to be used as a VGA
> > compatible device as an alternative to an emulated video device. QEMU
> > exposes this feature via a vfio device property 'display' with supported
> > values 'on/off/auto' (default is 'off').
> >
> > This patch adds the necessary bits to domain config handling in order to
> > expose this feature. Since there's no convenient way for libvirt to come
> > up with usable defaults for the display setting, simply because libvirt
> > is not able to figure out which of the display implementations - dma-buf
> > which requires OpenGL support vs vfio regions which doesn't need OpenGL
> > (works with OpenGL enabled too) - the underlying mdev uses.
> >
> > Signed-off-by: Erik Skultety <eskultet at redhat.com>
> > ---
...

> > +static int
> > +qemuDomainHostdevDefPostParse(const virDomainHostdevDef *hostdev,
> > +                              const virDomainDef *def)
> > +{
> > +    const virDomainHostdevSubsysMediatedDev *mdevsrc;
> > +
> > +    if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS) {
> > +        switch ((virDomainHostdevSubsysType) hostdev->source.subsys.type) {
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB:
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI:
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI:
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST:
> > +            break;
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV:
> > +            mdevsrc = &hostdev->source.subsys.u.mdev;
> > +            return qemuDomainHostdevMdevDefPostParse(mdevsrc, def);
> > +        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_LAST:
> > +        default:
> > +            virReportEnumRangeError(virDomainHostdevSubsysType,
> > +                                    hostdev->source.subsys.type);
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    return 0;
> > +}
> > +
>
> Again, these two ^^ are validate callbacks not PostParse. You are not
> filling in missing information, you are checking (=validating) whether
> user provided XML is valid.

Actually, both of them were, back in the RFC series I linked (I completely
agree with you) but I was asked to convert them to post parse so that xml2xml
test could fail for invalid XMLs. Let me know whether I should convert them
back.

Consider the rest fixed.

Erik